Field of the Disclosure
The present disclosure relates to a simulation apparatus that is attached to a machine tool and is configured to move a model of a movable structure being a constituent of the machine tool by manual operation.
Background of the Disclosure
In the field of NC (numerically controlled) machine tools, for example, in the case where machining is performed using an NC program, if there is any error in the NC program, then there is a possibility that a movable structure, e.g., a tool rest, a table, a spindle head or the like, that is driven and controlled in accordance with the NC program interferes with another structure. Therefore, in the case where machining is performed using a new NC program having no machining performance record, operation of the NC program is checked in advance.
Further, as a technique for performing the operation check (interference check), there has conventionally been employed a so-called simulation technique in which the presence of interfere is virtually checked by using a model of the machine tool and moving the model in accordance with the NC program.
Further, besides automatic operation using an NC program, machining by moving the movable structure by manual operation is also usually performed. Such machining by manual operation is basically performed under a situation where interference can be avoided because it is performed while an operator is visually checking the operation state of the movable structure. However, in the case of an operator lacking skills, interference can occur due to the operator's misoperation.
Therefore, there has conventionally been suggested an interference prevention method as disclosed in Japanese Unexamined Patent Application Publication No. 2007-249671 (hereinafter “the JP '671 application”) mentioned below. In the interference prevention method disclosed in the JP '671 application, a moving direction of a movable body is recognized based on its current position and a command by a manual operation, an intersection of a straight line extending in the moving direction from a current position of a three-dimensional model surface of the movable body and a three-dimensional model surface of an interfering structure is calculated, a no-entry area is set based on the intersection, and then the movable body is moved in the moving direction. When the movable body reaches a position in front of the no-entry area, a deceleration processing is automatically performed to stop the movement of the movable body and an alarm is emitted.